CHICAGO (AP) – The millions that businessman Bruce Rauner has raised for the Republican contest for Illinois governor have allowed him to flood the airwaves with television ads, but also have made him the main target of his opponents, who unloaded on the wealthy political newcomer during their first joint campaign appearance of 2014.

State Sens. Bill Brady and Kirk Dillard and state Treasurer Dan Rutherford jumped on Rauner on Thursday for everything from his flip-flop on raising the minimum wage to his daughter’s entrance in an elite high school, prompting Rauner to declare it “a little bit of a beat-up-Brucey morning.” The comments followed news conferences both Dillard and Brady held in the past week that focused solely on criticizing the equity investor from Winnetka.

Rauner called the attention a positive sign and said he expects it every day until the March 18 primary.

“The reason I’m being attacked is I’ve got a message that’s resonating with the voters, and we’ll win in the race,” he said during a breakfast forum in suburban Chicago hosted by the (Arlington Heights) Daily Herald and WLS-TV.

The attacks might be the best strategy available to his three rivals, who have lagged significantly behind in fundraising. Rauner raised more than $7 million last year – a total that includes about $2 million of his own money. Rutherford raised about $1.5 million, while Dillard brought in about $900,000 and Brady about $203,000.

“The only chance any of them has to beat Bruce Rauner is if everybody trains their fire on him directly,” said Republican strategist Doug O’Brien, who was a former chief aide to U.S. Sen. Mark Kirk.

But it’s uncertain who benefits from the approach.

Being singled out by the veteran lawmakers could strengthen Rauner’s image as the outsider who wants to “shake up Springfield.” And if none of the other candidates has money to break out of the pack, all of their efforts might just be drowned out by Rauner’s prolific messaging. Those ads – which have been running for weeks and include radio, Internet and social media in addition to TV – have focused on his plans to improve the economy, establish term limits for lawmakers and improve education.

“I don’t think any of them can get any traction as long as Rauner is up on TV talking about hot-button issues,” O’Brien said.

Brady said his focus on Rauner was necessary for the party, particularly on the minimum wage issue. At a candidate forum last month, Rauner said he’d support bringing Illinois’ $8.25 minimum wage rate down to the national rate of $7.25. Weeks later, he said he’d be in support of raising it under the right circumstances. Rauner has called the earlier stance “a mistake.”

“The Republican Party, not just Bruce Rauner, took a hit because of his position, whatever it might be, on minimum wage. It was damaging,” he told reporters after Thursday’s forum in Mount Prospect. “I had to defend the fact that Republicans don’t stand for cutting people’s wages.”

Dillard said his attention to Rauner is because of revelations about the candidate.

“I only react,” he said. “I don’t start it.”

Still, Dillard didn’t miss a chance to bring up allegations, including a recent Chicago Sun-Times investigation that showed Rauner made a $250,000 contribution to an elite Chicago public school after his daughter gained admission. Rauner’s campaign has confirmed he made the donation, but said it falls in line with his other contributions to schools and had nothing to do with the admission of his straight-A student daughter.

“It’s the constant drip drip drip of questions that, I think, will wash away in a flood any chance that our party has, if Bruce is the nominee, of defeating [Gov. Pat Quinn] in the fall,” Dillard said during the forum.

Rauner did level some accusations back at the three, including that all are political insiders tied to big union money. The move prompted Rutherford, whose attention on Rauner has been more subtle, to scold him mid-sentence.

Rauner has argued he is the only candidate who will be able to compete financially in the November general election with Gov. Pat Quinn, who faces no major challenger in the Democratic primary. Quinn raised about $1.9 million in the final three months of 2013, finishing the year with about $4.5 million.